Preparation method of high-temperature-resistant perfluoroether rubber

Abstract

The invention discloses a high-temperature-resistant perfluoroether rubber preparation method which comprises the following steps: mixing perfluoroether rubber, modified silicon carbide and modified boron nitride nanosheets, adding a cross-linking agent, uniformly mixing, and carrying out segmented vulcanization to obtain the high-temperature-resistant perfluoroether rubber, wherein in the preparation process of the modified boron nitride nanosheet, nano silicon carbide, the boron nitride nanosheet, polymethyl methacrylate, a catalyst and a solvent are uniformly mixed, the surface of a matrix is coated with the mixture, a thin film is formed through drying, the thin film is sintered and crushed, and an intermediate is obtained; and carrying out graft modification on the intermediate by using a silane coupling agent containing a carbon-carbon double bond to obtain the modified boron nitride nanosheet. The perfluoroether rubber prepared by the invention has good thermal conductivity, high temperature resistance and plasma resistance.

Description

Technical Field

[0001] The invention relates to the technical field of sealing components, and in particular to a method for preparing high-temperature resistant perfluoroether rubber. Background Art

[0002] In semiconductor manufacturing, the reliability of elastomeric seals is critical. It is extremely costly to stop production and replace seals. In order to avoid potential risks, the requirements for the cleanliness and purity of seals are very strict. At the same time, the seals must be able to work for a long time in plasma and high temperature environments.

[0003] Perfluoroether rubber is usually polymerized from a variety of monomers, including tetrafluoroethylene, a third vulcanization point monomer, and perfluoroalkyl (oxy) vinyl ether. The perfluoroalkyl vinyl ether may be perfluoromethyl vinyl ether, and the perfluoroalkoxy vinyl ether may be perfluoro-2-propoxy vinyl ether.

[0004] Perfluoroether rubber (FFKM) is the most heat-resistant (up to 325°C) and chemical-resistant (more than 1,800 kinds) synthetic elastomer today. It is also the most expensive (tens of thousands of yuan per kilogram) synthetic elastomer. The price of the same weight of products is close to gold. FFKM is often used in the semiconductor industry. After being corroded by high temperature and plasma, perfluoroether rubber is prone to cracks, and will quickly develop into through-type cracks under tension and compression, causing the rubber to break. Therefore, it is necessary to further improve the high temperature resistance and plasma resistance of perfluoroether rubber. Summary of the invention

[0005] Based on the technical problems existing in the background technology, the present invention proposes a method for preparing high-temperature resistant perfluoroether rubber. The perfluoroether rubber prepared by the present invention has good thermal conductivity, high-temperature resistance and plasma resistance.

[0006] The invention provides a method for preparing a high temperature resistant perfluoroether rubber, comprising the following steps: mixing perfluoroether rubber, modified silicon carbide and modified boron nitride nanosheets, adding a crosslinking agent and mixing, and vulcanizing in stages to obtain the high temperature resistant perfluoroether rubber; In the preparation process of modified boron nitride nanosheets, nano silicon carbide, boron nitride nanosheets, polymethyl methacrylate, a catalyst and a solvent are mixed, coated on the surface of a substrate, dried into a film, sintered and crushed to obtain an intermediate; the intermediate is grafted and modified with a silane coupling agent containing a carbon-carbon double bond to obtain a modified boron nitride nanosheet.

[0007] The third vulcanization point monomer of the perfluoroether rubber of the present invention is a bromine-containing vulcanization point monomer, such as bromotrifluoroethylene, 1-bromo-2,2-difluoroethylene, and the like.

[0008] Preferably, in the preparation process of modified boron nitride nanosheets, the weight ratio of nano silicon carbide, boron nitride nanosheets, polymethyl methacrylate, and catalyst is 2-2.5:10:3-4:0.4-0.5.

[0009] Preferably, in the preparation process of the modified boron nitride nanosheets, the catalyst is ferrocene.

[0010] Preferably, in the preparation process of the modified boron nitride nanosheets, the solvent is N-methylpyrrolidone.

[0011] Preferably, during the preparation of the modified boron nitride nanosheets, the sintering is performed at 700-750° C. for 30-40 min.

[0012] Preferably, during the preparation of the modified boron nitride nanosheets, sintering is performed in an inert gas atmosphere.

[0013] Preferably, the modified silicon carbide is silicon carbide modified by a silane coupling agent containing a carbon-carbon double bond.

[0014] The silane coupling agent containing a carbon-carbon double bond may be γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, or the like.

[0015] Preferably, the weight ratio of the modified silicon carbide to the modified boron nitride nanosheets is 40-45:8-10.

[0016] Preferably, the weight ratio of perfluoroether rubber to modified silicon carbide is 100:40-45.

[0017] Preferably, the weight ratio of perfluoroether rubber to cross-linking agent is 100:3-4.

[0018] Preferably, the crosslinking agent is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and triallyl isocyanurate.

[0019] The raw materials of the high temperature resistant perfluoroether rubber may further contain plasticizers, antioxidants and the like.

[0020] Preferably, vulcanization is performed at 160-165°C for 8-12 minutes, and second-stage vulcanization is performed at 200-220°C for 20-24 hours.

[0021] The invention mixes nano silicon carbide, boron nitride nano sheets, polymethyl methacrylate and a catalyst to form a film, then sintering and catalyzing the polymethyl methacrylate to convert it into carbon nanotubes, and the carbon nanotubes are evenly distributed between the boron nitride nano sheet layers, while the nano silicon carbide is evenly distributed on the surface and between the layers of the boron nitride nano sheet. The distribution state of the three can form interconnected heat conduction channels on the surface layer and the gap between the layers of the boron nitride nano sheet, thereby greatly improving the thermal conductivity of the boron nitride nano sheet; and the distribution states of the three can cooperate with each other to improve the plasma resistance performance; and then the compatibility with perfluoroether rubber can be improved by grafting modification with a silane coupling agent containing a carbon-carbon double bond; Moreover, the modified boron nitride nanosheets grafted with carbon-carbon double bonds and the modified silicon carbide grafted with carbon-carbon double bonds can have good compatibility with perfluoroether rubber on the one hand, and can cooperate with 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and triallyl isocyanurate on the other hand, and graft cross-link with the vulcanization point of the perfluoroether rubber, so that the modified silicon carbide and modified boron nitride nanosheets are evenly distributed along the main chain of the perfluoroether rubber to form a continuous heat conduction channel and plasma barrier layer, which can transfer heat away, thereby greatly improving the high temperature resistance and plasma resistance of the perfluoroether rubber; and its even distribution along the main chain of the perfluoroether rubber can greatly improve the toughness and strength of the rubber, and avoid the problem of cracks that are easy to form and cause rubber breakage after the rubber is corroded by plasma. DETAILED DESCRIPTION

[0022] The technical solutions of the present invention are described in detail below through specific embodiments. However, it should be clearly stated that these embodiments are for illustration only and are not to be construed as limiting the scope of the present invention.

[0023] Example 1

[0024] A method for preparing high temperature resistant perfluoroether rubber comprises the following steps: Nano-silicon carbide, boron nitride nanosheets, polymethyl methacrylate, and ferrocene are mixed in a weight ratio of 2:10:3:0.4, then added into N-methylpyrrolidone, ultrasonically dispersed for 30 minutes, stirred for 4 hours, then coated on the surface of the substrate, and dried into a thin film; then the thin film is sintered at 750° C. for 30 minutes in an argon atmosphere, and then crushed after cooling to room temperature to obtain an intermediate; The intermediate was added into a 5 wt% ethanol-water solution of γ-methacryloxypropyltrimethoxysilane (90:10 v / v), stirred at 60°C for 1 h, centrifuged, washed with water, and dried to obtain modified boron nitride nanosheets; The raw materials were mixed according to the weight ratio of perfluoroether rubber, γ-methacryloxypropyltrimethoxysilane modified silicon carbide, modified boron nitride nanosheets, plasticizer carnauba wax, and antioxidant RD being 100:45:8:5:1, and then 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and triallyl isocyanurate were added according to the weight ratio of perfluoroether rubber, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and triallyl isocyanurate being 100:1:3, and the mixture was mixed. The mixture was vulcanized at 165°C for 8 minutes and then vulcanized in a second stage at 220°C for 20 hours to obtain a high temperature resistant perfluoroether rubber.

[0025] Example 2

[0026] A method for preparing high temperature resistant perfluoroether rubber comprises the following steps: Nano-silicon carbide, boron nitride nanosheets, polymethyl methacrylate, and ferrocene are mixed in a weight ratio of 2.5:10:4:0.5, then added into N-methylpyrrolidone, ultrasonically dispersed for 30 minutes, stirred for 4 hours, then coated on the surface of the substrate, and dried into a thin film; then the film is sintered at 700° C. for 40 minutes in an argon atmosphere, and then crushed after cooling to room temperature to obtain an intermediate; The intermediate was added into a 5 wt% ethanol-water solution of γ-methacryloxypropyltrimethoxysilane (90:10 v / v), stirred at 60°C for 1 h, centrifuged, washed with water, and dried to obtain modified boron nitride nanosheets; The raw materials were mixed according to the weight ratio of perfluoroether rubber, γ-methacryloxypropyltrimethoxysilane modified silicon carbide, modified boron nitride nanosheets, plasticizer carnauba wax, and antioxidant RD being 100:40:10:5:1, and then 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and triallyl isocyanurate were added according to the weight ratio of perfluoroether rubber, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and triallyl isocyanurate being 100:1:2, and the mixture was mixed. The mixture was vulcanized at 160°C for 12 minutes and then vulcanized at 200°C for 24 hours to obtain a high temperature resistant perfluoroether rubber.

[0027] Example 3

[0028] A method for preparing high temperature resistant perfluoroether rubber comprises the following steps: Nano-silicon carbide, boron nitride nanosheets, polymethyl methacrylate, and ferrocene are mixed in a weight ratio of 2.2:10:3.5:0.5, then added into N-methylpyrrolidone, ultrasonically dispersed for 30 minutes, stirred for 4 hours, then coated on the surface of the substrate, and dried into a thin film; then, the thin film is sintered at 730° C. for 35 minutes in an argon atmosphere, and then crushed after cooling to room temperature to obtain an intermediate; The intermediate was added into a 5 wt% ethanol-water solution of γ-methacryloxypropyltrimethoxysilane (90:10 v / v), stirred at 60°C for 1 h, centrifuged, washed with water, and dried to obtain modified boron nitride nanosheets; The raw materials were mixed according to the weight ratio of perfluoroether rubber, γ-methacryloxypropyltrimethoxysilane modified silicon carbide, modified boron nitride nanosheets, plasticizer carnauba wax, and antioxidant RD being 100:42:9:5:1, and then 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and triallyl isocyanurate were added according to the weight ratio of perfluoroether rubber, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and triallyl isocyanurate being 100:1:2.5, and the mixture was mixed. The mixture was vulcanized at 165°C for 10 minutes and then vulcanized in a second stage at 210°C for 22 hours to obtain a high temperature resistant perfluoroether rubber.

[0029] Comparative Example 1 A method for preparing high temperature resistant perfluoroether rubber comprises the following steps: It does not contain γ-methacryloxypropyltrimethoxysilane-modified silicon carbide and modified boron nitride nanosheets, and the rest is the same as Example 3.

[0030] Comparative Example 2 A method for preparing high temperature resistant perfluoroether rubber comprises the following steps: The “modified boron nitride nanosheets” are replaced by “γ-methacryloxypropyltrimethoxysilane modified silicon carbide”, and the rest are the same as in Example 3.

[0031] Comparative Example 3 A method for preparing high temperature resistant perfluoroether rubber comprises the following steps: Replace “γ-methacryloxypropyltrimethoxysilane modified silicon carbide” with “modified boron nitride nanosheets”, and the rest is the same as Example 3.

[0032] Comparative Example 4 A method for preparing high temperature resistant perfluoroether rubber comprises the following steps: Add the boron nitride nanosheets to a 5 wt% solution of γ-methacryloxypropyltrimethoxysilane in ethanol and water (90:10 v / v), stir at 60° C. for 1 h, centrifuge, wash with water, and dry to obtain modified boron nitride nanosheets; the rest is the same as in Example 3.

[0033] The perfluoroether rubbers prepared in Examples 1-3 and Comparative Examples 1-4 were tested for their properties, and the results are shown in Table 1.

[0034] Plasma resistance experiment: The rubber is placed on the reaction table of the plasma etcher, the heating plate temperature is 200°C, RPS 6000W, the gas is NF3, the flow rate is 3000sccm, and the etching is carried out for 48 hours; then the weight loss rate, cracks and compression permanent deformation of the rubber are tested.

[0035] Table 1 Test results

[0036] It can be seen from Table 1 that the high temperature resistant perfluoroether rubber prepared in the present invention has good high temperature resistance, plasma resistance and mechanical properties.

[0037] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing high temperature resistant perfluoroether rubber, characterized in that: The method comprises the following steps: mixing perfluoroether rubber, modified silicon carbide and modified boron nitride nanosheets, adding a crosslinking agent and mixing evenly, and vulcanizing in sections to obtain high temperature resistant perfluoroether rubber; In the preparation process of modified boron nitride nanosheets, nano silicon carbide, boron nitride nanosheets, polymethyl methacrylate, a catalyst and a solvent are mixed, coated on the surface of a substrate, dried into a film, sintered and crushed to obtain an intermediate; the intermediate is grafted and modified with a silane coupling agent containing a carbon-carbon double bond to obtain a modified boron nitride nanosheet.

2. The method for preparing high temperature resistant perfluoroether rubber according to claim 1, characterized in that: In the preparation process of modified boron nitride nanosheets, the weight ratio of nano silicon carbide, boron nitride nanosheets, polymethyl methacrylate and catalyst is 2-2.5:10:3-4:0.4-0.

5.

3. The method for preparing high temperature resistant perfluoroether rubber according to claim 1 or 2, characterized in that: In the preparation process of modified boron nitride nanosheets, the catalyst is ferrocene.

4. The method for preparing high temperature resistant perfluoroether rubber according to claim 1 or 2, characterized in that: In the preparation process of the modified boron nitride nanosheets, the solvent is N-methylpyrrolidone.

5. The method for preparing high temperature resistant perfluoroether rubber according to claim 1 or 2, characterized in that: During the preparation of the modified boron nitride nanosheets, the nanosheets are sintered at 700-750° C. for 30-40 minutes.

6. The method for preparing high temperature resistant perfluoroether rubber according to claim 1 or 2, characterized in that: During the preparation of the modified boron nitride nanosheets, sintering is performed in an inert gas atmosphere.

7. The method for preparing high temperature resistant perfluoroether rubber according to claim 1 or 2, characterized in that: The modified silicon carbide is silicon carbide modified by a silane coupling agent containing a carbon-carbon double bond.

8. The method for preparing high temperature resistant perfluoroether rubber according to claim 1 or 2, characterized in that: The weight ratio of the modified silicon carbide to the modified boron nitride nanosheets is 40-45:8-10.

9. The method for preparing high temperature resistant perfluoroether rubber according to claim 1 or 2, characterized in that: The weight ratio of perfluoroether rubber to modified silicon carbide is 100:40-45.

10. The method for preparing high temperature resistant perfluoroether rubber according to claim 1 or 2, characterized in that: The weight ratio of perfluoroether rubber to cross-linking agent is 100:3-4.

Images